Discovering new plants: A is for....

Abelia

Welcome to another project of mine for this year. Now I grow a lot of plants, in my own and others' gardens: but for some years now, they've all been pretty much the same plants. I've added a few to my repertoire, but they've usually been plants I know a lot about already, so they're a pretty safe bet (and I've usually wanted to grow them for ages, finally got my hands on them... you know the drill).

It occurred to me some time about the end of last year that this might not be a very good thing. There are definite and really quite gaping gaps in my plant knowledge: I have never in my life, for example, grown a Deutzia of any description, even though they're common as muck.

So I figured this year I'd change all that. I've picked up my well-thumbed bible, aka the Readers Digest New Encyclopaedia of Garden Plants and Flowers, and I'm going to work my way through the alphabet picking a new (for me) genus for each letter to get to know in my garden. It's a bit random, as plant studies go, but it'll have to do.

So this month I've been off shopping for Abelias. A relative of the honeysuckle according to the late great Fred Whitsey, it's late-summer flowering, some borderline hardy, but relishing conditions just such as I have in my garden - i.e. well-drained and sunny.

There are lots of them but I've gone for A. x grandiflora - a hybrid between A. chinensis and A. uniflora. Mr Whitsey says all abelias are named for a Dr Clarke-Abel who worked as a surgeon to a Chinese mission in the early 1800s (now that must have been a heck of a job). For light relief he went off plant collecting, and came back with A. chinensis - borderline hardy, very pale pink, and a bit pretty for my liking. Actually he didn't quite come back with them as he was shipwrecked on the way home and lost his seeds, which seems a bit unfair, but luckily he'd already given some to a friend so they made it back to the UK without him.

Anyway: A. x grandiflora has an AGM which makes me well-disposed towards it right from the start. It's semi-evergreen, only dropping its leaves in very cold winters, and looks a bit like a slightly chunky evergreen spiraea, if you can imagine such a thing.

Browsing around the garden centre I could only see variegated abelias with leaves in bilious shades of mottled pink and cream which rather put me off. But luckily in a corner there was a little shrub with vibrant non-variegated yellow leaves: promising, except abelias are known to be pink, and yellow leaves with pink flowers is the combination from hell (hide your head in shame, Spiraea japonica 'Goldflame'). On closer inspection, though, the label says the flowers on this one are white: and what's more it has "bronze-gold" leaves in autumn. Mmmmm.... sounds lovely.

Clutching my purchase I made a bee-line as soon as I got home for my online RHS Plantfinder only to find that the cultivar, 'Brockhill Allgold', isn't listed anywhere. I appear to have chosen a fictitious plant.

Well, it's not the most promising start to my voyage of discovery. But it'll have to do. I shall keep you updated with how I'm getting on with all my new kids on the block later in the year.

Scary gardening

I got called a scary gardener the other day. That was by a client of mine when she saw what I'd done to her forsythia.

The trouble is, I keep getting asked to put right the effects of years of neglect. This inevitably means reducing large, overcongested shrubs to a fraction of their original size and density.

This is of course very good for the shrub: you cut out all the dead wood that's been suffocating it for so long, you let air and light into the centre from where it'll send up lots of lovely new young shoots (especially now it has room to do so), and particularly in the case of this forsythia, you restore some of the natural shape to the plant. The forsythia in question had been given a haircut once a year for several decades, which involved clipping the top to a blobby kind of dome shape and cutting off a large proportion of next year's flowers in the process. The centre of the shrub was so congested you couldn't see between the branches, and it had also more or less stopped flowering.

In my defence, I had intended to go quite easy on it - forsythia don't normally enjoy being very hard pruned, so I usually only remove a couple of the thickest branches. But in this case the decision was made for me: once I got up close and personal with the centre of the shrub, I discovered that at least half of it was dead. Once I'd removed that, there was a bloomin' great hole in the middle, so in the end the only live branches I had to remove were to re-balance the shrub again.

Result: a much healthier, but much reduced forsythia. The owner came out to see what I'd been up to, and gasped.

"Oh... my.... god.... " she croaked, for some reason clutching her throat.

At this point I began stumbling over myself in my haste to reassure her that it would be much happier now, produce lots more flowers next year, would actually move in the wind rather than just sitting there in an approximation of rigor mortis... etc etc etc. Whereupon she called me a scary gardener.

Well... I shall be suitably smug next April and May when it's smothered in tons of yellow flowers. Honestly, it's a good thing I don't require any thanks for this job....

Pruning as art

I'm well into the March pruning season now - have so far tackled dogwoods, coppiced eucalyptus, hebes, mahonias, hydrangeas, buddlejas and an overgrown berberis (that one was as truly horrible a job as it gets). I have yet to take the secateurs to a deciduous ceanothus or two, a cotinus, a small field of hypericum, and several pyracantha. I'm sure I'll spot a few more before I'm done.

It took me quite a while to realise that pruning is an art form (and I'm not talking about the really arty stuff like cloud pruning or topiary - just common or garden keeping your shrubs in check pruning). One injudicious snip and the balance of a shrub is ruined - usually if you chop off a branch you weren't intending to you actually end up starting again, as you then have to re-balance the shrub to make amends for your mistake.

So when I'm pruning I take my time. I do an awful lot of standing back and pondering with my head on one side, à la van Gogh (told you it was an art form). This is because once you prune out one big-ish branch, if you take a step back and look at the whole shrub, it suddenly becomes glaringly obvious which branch is now sticking out like a sore thumb and needs to be pruned out as well. Eventually - hopefully - you get to an equilibrium, where all the branches are evenly spaced, there's plenty of air and light in the centre of the shrub, it's not too tall or too wide, and looks just right (if considerably slimmer than when you started).

Of course there are shrubs which provide a little light relief to all this nailbiting judgement malarky - cornus, buddleja and coppiced eucalyptus you can just gaily slash back to a bud somewhere between 6" - 36" above ground level with no thought to aesthetic delicacies. But treat all shrubs with such reckless abandon - as, I find, most white van gardeners do - and you end up with a stubby stump of brushwood which does no aesthetic favours to anyone and won't help the health of the shrub, either. Take three, or even four times as long over doing it, and you'll have not a pruned shrub, but a work of art. It's a creative business, this gardening lark.

Plant of the month - January

Pyracantha 'Saphyr Jaune'

These little jewels have been cheering up my garden since last autumn. Pyracantha can be the only really bright colour shining through the dull months of winter, and they're all the more welcome for that. The birds have snaffled the red and orange berries already - I have P. 'Saphyr Orange' and P. 'Saphyr Rouge' planted along the same fence, and they're meant to mix 'n' mingle, but the yellow is all that's left. No complaints here, though - I'm just grateful to have such a dainty little sprinkling of colour at this time of year.

Pyracantha is one of those shrubs which is doing something useful all year round. I keep mine trained against the fence - I find they become badly-behaved thugs in the border if left unsupervised. If you're strict with them, though, they behave themselves beautifully. They're one of the few plants which provides evergreen climbing cover all year, and as a sideline are excellent security - climb over a fence clad in pyracantha and you won't forget it in a hurry. As if that wasn't enough, they froth up with flowers in early summer and then sparkle all winter too. I wouldn't be without them.

Keeping trees in check

I spent a happy hour or two with the chainsaw the other day, converting an ill-advised pollard into a coppice in a client's garden.

The difference between pollarding and coppicing is pretty straightforward, though people tend to get a bit confused in a "stalactites and stalagmites" sort of way. Pollarding is when you allow the tree to develop a single trunk, and then when it's got to the height you want, you cut the leader to that point and allow it to grow new shoots from there. It's good if you want to limit the height of a tree yet allow it to provide some screening too.

Another client has a row of pollarded lime trees growing right the way along the length of her garden: very elegant, and with a little judicious pruning of the inevitable wispy sideshoots that sprout from the trunk from time to time, it's easy to keep them good-looking all year round. Willow also makes a good pollard: a local willow producer grows pollarded willows all along the streams in the field behind his house and harvests the stems each winter for use in basket-weaving.

It doesn't work for all trees, though. The client I visited the other day had tried to pollard a hazel tree, which doesn't lend itself to the process well at all. Hazels sprout like crazy from all up the trunk and from the base as well as soon as you try to limit their growth, meaning you quickly get not an elegant column but more of a bizarre upright hedge effect. In this particular case, the client had allowed one or two of these shoots to develop and pollarded those too, so you ended up with a multi-stemmed pollard, complete with wild beardy clumps on the trunks, if you can imagine such a thing: not a pretty sight.

With hazels it's much better to exploit the naturally multi-stemmed habit and coppice them. This involves cutting the whole tree down to about 6" above ground, which looks drastic, but then next spring it produces a lovely spray of even, whippy shoots to the same height all round, giving a shapely shrub-like effect. You allow this to grow on for 2-3 years, and then do it all over again (and use the wonderful straight stems for beanpoles while you're at it). An alternative, if you don't fancy losing your hazel completely every 3 years, is to take out a third of the stems each year - choose the thickest or any which cross other stems or grow in the wrong direction. That way every three years you'll have rejuvenated the whole coppice anyway.

The coppicing technique can be used to keep otherwise wayward trees like eucalyptus in check (the young leaves it produces when treated this way are fabulous too). And if you coppice willow and dogwood, you'll make the most of the vibrant coloured stems they produce in winter. Pretty and practical, too!

Choice choisya

Another good shrub for cutting back at this time of year is Choisya ternata "Sundance". About now those lovely sunny yellow leaves which lifted your spirits through the worst of the winter weather turn a pale washed-out shade of sickly. It's time to prune them off and allow the new, green growth to come through and turn yellow in its place. It also gives the bush a lovely rounded shape for next winter, as the new growth comes through in nice neat rosettes and all stays the same length, more or less.

It's pretty simple - just take the secateurs and trim down to the next rosette of leaves, usually about 6" or so down the stem. If there isn't a rosette, just trim out the whole stem. You don't need to cut it back hard: just shape it to the size you'd like and leave it.

Choisya is one of the few shrubs you can hack back without ruining the appearance: though it does change colour temporarily, from yellow to green, a healthy plant carries enough leaves in the centre of the bush to keep it looking nice and dense. After you've finished, give it a feed of pelleted chicken manure and a good water and mulch, and it'll be set fair to keep you smiling in winter all over again.

Hacking at lilacs

This is a great time of year for cutting back overgrown shrubs, especially spring-flowering ones. Lilac is a prime target, as well as evergreen ceanothus, berberis, pyracantha... pretty much anything that doesn't flower later this year, really.

I spent a couple of hours laying into a client's lilac last week. It must have been 20 years old, and about that long since it was last looked at: it was heavily congested in the centre and the 4" thick branches were splaying outward and endangering his shed. And it was about 25-30ft tall, which would have been fine in a big garden but his is a small-ish suburban strip.

I like to think of this kind of pruning as rejuvenating pruning - though it also counts as common-or-garden hacking back. What you do is remove about a third to a half of the wood - taking out the thickest, oldest branches first, and then any which are pointing in the wrong direction, as well as any which are diseased and/or dead, of course. If you're me, you find it hard to know when to stop, especially with lilacs: when they're overgrown, they tend to develop long, leggy stems with the leaves and flowers right at the very end, and that means once you've taken out the bulk of the shrub, you're left with some rather sad-looking whippy lengths of wood waving around in the breeze. It all looks very odd.

Fear not: this is quite normal. The thing to do is to leave it looking a bit wierd this year, and wait until the stump starts pushing up new growth, which it will do very quickly. Then next year you can cut out another third of the long whippy old wood; and by the third year, when the new growth has got to a decent height and will be flowering well, you can take out the last third to be left with a bush that's all the same height, hopefully a nice shape and full of strapping young growth which looks far nicer and is much more healthy.

Back to the wall

I've been giving my ceanothus a haircut this week, as it's trained against a fence and needs an annual prune to keep it tidy.

Wall-training shrubs which are otherwise inclined to get a bit big and unwieldy is a great way to keep them in bounds. Ceanothus is a good candidate, and so is Japanese quince (Chaenomeles japonica), pyracantha and Garrya elliptica. The small-leaved cotoneaster, C. horizontalis, holds itself so rigid it practically stands up against a wall by itself, without supports.

The principle is pretty straightforward: you'll need supports, such as wires spaced about a foot to 18" apart, to train the shrub onto before you start.

Then, year by year, you shape the shrub so it's flat against the wall. You do this just after flowering: just prune out any branches growing out away from the wall completely or, if you're at risk of ending up with bare stems, you can prune back to one or two leaf joints from the stem.

Tie in side shoots pointing the way you want them to go, and then trim any upward-growing stems to about an inch (2.5cm) below the top of the fence or wall. If any longer side shoots are growing beyond the bounds you want them to keep to, shorten them, too.

Pyracantha in particular makes a really lovely espalier if you do this: ceanothus is a bit more bushy, so you get a pleasing evergreen "coat" to disguise your fence with. In any case, you avoid the problem you get with climbers where they're forever climbing next door, or over the neighbouring shrubs; and it looks great, too.